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Commit 5d1952ac authored by Uma Krishnan's avatar Uma Krishnan Committed by Martin K. Petersen
Browse files

cxlflash: Reorder user context initialization 



In order to support cxlflash in the PowerVM environment, underlying
hypervisor APIs have imposed a kernel API ordering change.

For the superpipe access to LUN, user applications need a context.
The cxlflash module creates this context by making a sequence of
cxl calls. In the current code, a context is initialized via
cxl_dev_context_init() followed by cxl_process_element(), a function
that obtains the process element id. Finally, cxl_start_work()
is called to attach the process element.

In the PowerVM environment, a process element id cannot be obtained
from the hypervisor until the process element is attached. The
cxlflash module is unable to create contexts without a valid
process element id.

To fix this problem, cxl_start_work() is called before obtaining
the process element id.

Signed-off-by: default avatarUma Krishnan <ukrishn@linux.vnet.ibm.com>
Acked-by: default avatarMatthew R. Ochs <mrochs@linux.vnet.ibm.com>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
parent 8a96b52a

drivers/scsi/cxlflash/superpipe.c

+28 −28
Original line number Diff line number Diff line
@@ -1386,6 +1386,13 @@ static int cxlflash_disk_attach(struct scsi_device *sdev, 
		goto out_attach;

	}



	ctxi = create_context(cfg);

	if (unlikely(!ctxi)) {

		dev_err(dev, "%s: Failed to create context! (%d)\n",

			__func__, ctxid);

		goto err;

	}



	ctx = cxl_dev_context_init(cfg->dev);

	if (IS_ERR_OR_NULL(ctx)) {

		dev_err(dev, "%s: Could not initialize context %p\n",
@@ -1394,6 +1401,17 @@ static int cxlflash_disk_attach(struct scsi_device *sdev, 
		goto err;

	}



	work = &ctxi->work;

	work->num_interrupts = attach->num_interrupts;

	work->flags = CXL_START_WORK_NUM_IRQS;



	rc = cxl_start_work(ctx, work);

	if (unlikely(rc)) {

		dev_dbg(dev, "%s: Could not start context rc=%d\n",

			__func__, rc);

		goto err;

	}



	ctxid = cxl_process_element(ctx);

	if (unlikely((ctxid >= MAX_CONTEXT) || (ctxid < 0))) {

		dev_err(dev, "%s: ctxid (%d) invalid!\n", __func__, ctxid);
@@ -1411,27 +1429,9 @@ static int cxlflash_disk_attach(struct scsi_device *sdev, 
	/* Translate read/write O_* flags from fcntl.h to AFU permission bits */

	perms = SISL_RHT_PERM(attach->hdr.flags + 1);



	ctxi = create_context(cfg);

	if (unlikely(!ctxi)) {

		dev_err(dev, "%s: Failed to create context! (%d)\n",

			__func__, ctxid);

		goto err;

	}



	/* Context mutex is locked upon return */

	init_context(ctxi, cfg, ctx, ctxid, fd, file, perms);



	work = &ctxi->work;

	work->num_interrupts = attach->num_interrupts;

	work->flags = CXL_START_WORK_NUM_IRQS;



	rc = cxl_start_work(ctx, work);

	if (unlikely(rc)) {

		dev_dbg(dev, "%s: Could not start context rc=%d\n",

			__func__, rc);

		goto err;

	}



	rc = afu_attach(cfg, ctxi);

	if (unlikely(rc)) {

		dev_err(dev, "%s: Could not attach AFU rc %d\n", __func__, rc);
@@ -1532,24 +1532,24 @@ static int recover_context(struct cxlflash_cfg *cfg, struct ctx_info *ctxi) 
		goto out;

	}



	rc = cxl_start_work(ctx, &ctxi->work);

	if (unlikely(rc)) {

		dev_dbg(dev, "%s: Could not start context rc=%d\n",

			__func__, rc);

		goto err1;

	}



	ctxid = cxl_process_element(ctx);

	if (unlikely((ctxid >= MAX_CONTEXT) || (ctxid < 0))) {

		dev_err(dev, "%s: ctxid (%d) invalid!\n", __func__, ctxid);

		rc = -EPERM;

		goto err1;

		goto err2;

	}



	file = cxl_get_fd(ctx, &cfg->cxl_fops, &fd);

	if (unlikely(fd < 0)) {

		rc = -ENODEV;

		dev_err(dev, "%s: Could not get file descriptor\n", __func__);

		goto err1;

	}



	rc = cxl_start_work(ctx, &ctxi->work);

	if (unlikely(rc)) {

		dev_dbg(dev, "%s: Could not start context rc=%d\n",

			__func__, rc);

		goto err2;

	}
@@ -1594,10 +1594,10 @@ static int recover_context(struct cxlflash_cfg *cfg, struct ctx_info *ctxi) 
	return rc;



err3:

	cxl_stop_context(ctx);

err2:

	fput(file);

	put_unused_fd(fd);

err2:

	cxl_stop_context(ctx);

err1:

	cxl_release_context(ctx);

	goto out;